runsvdir: fx a recent vda's buglet (was pausing even if not signaled).

 stop spawning children immediately if signaled. Kill one global.

1 files changed, 42 insertions, 34 deletions

diff --git a/runit/runsvdir.c b/runit/runsvdir.c
index 29e747fc1..e7f8d5ac9 100644
--- a/runit/runsvdir.c
+++ b/runit/runsvdir.c
@@ -58,7 +58,6 @@ struct globals {
         struct pollfd pfd[1];
         unsigned stamplog;
 #endif
-        smallint need_rescan; /* = 1; */
         smallint set_pgrp;
 };
 #define G (*(struct globals*)&bb_common_bufsiz1)
@@ -70,10 +69,8 @@ struct globals {
 #define logpipe     (G.logpipe     )
 #define pfd         (G.pfd         )
 #define stamplog    (G.stamplog    )
-#define need_rescan (G.need_rescan )
 #define set_pgrp    (G.set_pgrp    )
 #define INIT_G() do { \
-        need_rescan = 1; \
 } while (0)
 
 static void fatal2_cannot(const char *m1, const char *m2)
@@ -96,21 +93,27 @@ static void warnx(const char *m1)
 }
 #endif
 
-static void runsv(int no, const char *name)
+/* inlining + vfork -> bigger code */
+static NOINLINE pid_t runsv(const char *name)
 {
-        pid_t pid = vfork();
+        pid_t pid;
+
+        /* If we got signaled, stop spawning children at once! */
+        if (bb_got_signal)
+                return 0;
 
+        pid = vfork();
         if (pid == -1) {
                 warn2_cannot("vfork", "");
-                return;
+                return 0;
         }
         if (pid == 0) {
                 /* child */
                 if (set_pgrp)
                         setsid();
 /* man execv:
- * Signals set to be caught by the calling process image
- * shall be set to the default action in the new process image.
+ * "Signals set to be caught by the calling process image
+ *  shall be set to the default action in the new process image."
  * Therefore, we do not need this: */
 #if 0
                 bb_signals(0
@@ -121,20 +124,22 @@ static void runsv(int no, const char *name)
                 execlp("runsv", "runsv", name, NULL);
                 fatal2_cannot("start runsv ", name);
         }
-        sv[no].pid = pid;
+        return pid;
 }
 
-static void do_rescan(void)
+/* gcc 4.3.0 does better with NOINLINE */
+static NOINLINE int do_rescan(void)
 {
         DIR *dir;
         direntry *d;
         int i;
         struct stat s;
+        int need_rescan = 0;
 
         dir = opendir(".");
         if (!dir) {
                 warn2_cannot("open directory ", svdir);
-                return;
+                return 1; /* need to rescan again soon */
         }
         for (i = 0; i < svnum; i++)
                 sv[i].isgone = 1;
@@ -152,47 +157,47 @@ static void do_rescan(void)
                 }
                 if (!S_ISDIR(s.st_mode))
                         continue;
+                /* Do we have this service listed already? */
                 for (i = 0; i < svnum; i++) {
                         if ((sv[i].ino == s.st_ino)
 #if CHECK_DEVNO_TOO
                          && (sv[i].dev == s.st_dev)
 #endif
                         ) {
-                                sv[i].isgone = 0;
-                                if (!sv[i].pid)
-                                        runsv(i, d->d_name);
-                                break;
+                                if (sv[i].pid == 0) /* restart if it has died */
+                                        goto run_ith_sv;
+                                sv[i].isgone = 0; /* "we still see you" */
+                                goto next_dentry;
                         }
                 }
-                if (i == svnum) {
-                        /* new service */
+                { /* Not found, make new service */
                         struct service *svnew = realloc(sv, (i+1) * sizeof(*sv));
                         if (!svnew) {
                                 warn2_cannot("start runsv ", d->d_name);
+                                need_rescan = 1;
                                 continue;
                         }
                         sv = svnew;
                         svnum++;
-                        memset(&sv[i], 0, sizeof(sv[i]));
-                        sv[i].ino = s.st_ino;
 #if CHECK_DEVNO_TOO
                         sv[i].dev = s.st_dev;
 #endif
-                        /*sv[i].pid = 0;*/
-                        /*sv[i].isgone = 0;*/
-                        runsv(i, d->d_name);
-                        need_rescan = 1;
+                        sv[i].ino = s.st_ino;
+ run_ith_sv:
+                        sv[i].pid = runsv(d->d_name);
+                        sv[i].isgone = 0;
                 }
+ next_dentry: ;
         }
         i = errno;
         closedir(dir);
-        if (i) {
+        if (i) { /* readdir failed */
                 warn2_cannot("read directory ", svdir);
-                need_rescan = 1;
-                return;
+                return 1; /* need to rescan again soon */
         }
 
-        /* Send SIGTERM to runsv whose directories were not found (removed) */
+        /* Send SIGTERM to runsv whose directories
+         * were no longer found (-> must have been removed) */
         for (i = 0; i < svnum; i++) {
                 if (!sv[i].isgone)
                         continue;
@@ -201,8 +206,8 @@ static void do_rescan(void)
                 svnum--;
                 sv[i] = sv[svnum];
                 i--; /* so that we don't skip new sv[i] (bug was here!) */
-                need_rescan = 1;
         }
+        return need_rescan;
 }
 
 int runsvdir_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
@@ -219,6 +224,7 @@ int runsvdir_main(int argc UNUSED_PARAM, char **argv)
         unsigned now;
         unsigned stampcheck;
         int i;
+        int need_rescan = 1;
 
         INIT_G();
 
@@ -284,10 +290,9 @@ int runsvdir_main(int argc UNUSED_PARAM, char **argv)
                                 break;
                         for (i = 0; i < svnum; i++) {
                                 if (pid == sv[i].pid) {
-                                        /* runsv has gone */
+                                        /* runsv has died */
                                         sv[i].pid = 0;
                                         need_rescan = 1;
-                                        break;
                                 }
                         }
                 }
@@ -306,19 +311,20 @@ int runsvdir_main(int argc UNUSED_PARAM, char **argv)
                                                 last_mtime = s.st_mtime;
                                                 last_dev = s.st_dev;
                                                 last_ino = s.st_ino;
-                                                need_rescan = 0;
                                                 //if (now <= mtime)
                                                 //      sleep(1);
-                                                do_rescan();
+                                                need_rescan = do_rescan();
                                                 while (fchdir(curdir) == -1) {
                                                         warn2_cannot("change directory, pausing", "");
                                                         sleep(5);
                                                 }
-                                        } else
+                                        } else {
                                                 warn2_cannot("change directory to ", svdir);
+                                        }
                                 }
-                        } else
+                        } else {
                                 warn2_cannot("stat ", svdir);
+                        }
                 }
 
 #if ENABLE_FEATURE_RUNSVDIR_LOG
@@ -354,6 +360,8 @@ int runsvdir_main(int argc UNUSED_PARAM, char **argv)
                 }
 #endif
                 switch (bb_got_signal) {
+                case 0: /* we are not signaled, business as usual */
+                        break;
                 case SIGHUP:
                         for (i = 0; i < svnum; i++)
                                 if (sv[i].pid)